Gesellschaft



E. HORN Jan. 18 1927.

TELEPHONE SYUSTEM Filed Sept. '7, 19255 7 Sh'ets-Sheetl -Iz'zuan fr- EET-15T Harn Jan. 1 2

18 9 7 E. HORN TELEPHONE SYSTEM Filed Sept.

im NQ 1,615,206 E. HORN 4 TELEPHONE SYSTEM v Filed sept. 7; 1925 rrlsmmsl-snia'et' 5 mwN.

Jan. 18, 1927.

Jan. 18, 1927.

E. HORN TELEPHONE SYSTEM Filed Sept. '7, 1923 '7 Sheet-Shet 4 Jan, 18, 1927. E HORN TELEPHONE SYSTEM Filed Sept. '7, 19213 '7' Sheets-Sheet 5 Imran U17- Eff-7T Harn NWS EN M S Jan. 18 1927.

E. HORN TELEPHONE SYSTEM Filed Sept. '7, 1925 7 Sheet-Shet 6 Jan. 19

18 27 E. HORN TELEPHONE SYSTEM Filed sept. 7, 1923 7 shams-sheet 7 Patented Jan. 18, 1927.

UNITED STATES PATENT OFFICE.

ERNST HORN, OF BERLIN, GER'MANY, ASSIGNOR T0 SIEMENS & HALSKE AKTIEN- GESELLSCHAFT, 0F VEBNERVERK, SIEMENSSTADT BEI BERLIN, GERMANY.

TELEPHONE SYSTEM.

Application filed September 7, 1923, Serial No. 661,445, and in Germany September 9, 19%2.

In telephone systems itis often required that in sonic cases a selecting` device be operated several times by number impulses from one point, wnile tor setting up other calls the selecting device remains atrest tor the duration ot the call atter it has been operated once. Such selectingdevices are tor instance the auxiliary digit switches, or `switching repeaters which in telephone areas havingl main and sub-exchangcs bring about the switching over ot the connection to con.- necting devices ot the local exchange when the transmission of particular trains ot impulses indicates that a local connection is to ie set up. The auxiliary digit switches can, however, also be used for cttecting certain circuit changes, e. determining the value ot a call and can connect up the meter operating device for Zone metering only when particular trains of impulses are transmitted.

In known circuit arrangements it is necessary for auxiliary relays to beA energized in the positions in which the switch stops, these relays bringing the driving magnet ot the selecting device under the control ot the calling station for further trains ot impulses also. The number ot these relays considerably increases `the capital cost ot such a system.

Now the object of the present invention is to avoid increasing;` the capital cost ot such a system due to auxiliary and switching relays, thereby increasing the coinniercial eiliciency ot the system. This is achieved since aiiter the selectingl devices have been set on particular contacts, they are automatical y moved into a deiinite position from which they are moved onwards again under the control ot' further trains ct imgulses transmitted from the callin r station.'

The drawings show one method oit carr finnl out the invention.

In Figs. 1 t-o 4 are shown the circuits concerned in setting up ditlerent connections.

Fig. 3 shows the relative position oit the main and sub-exchanges, illustrating in solid lines the route over which connections are .l milished, and in interrupted lines the actual distance between the exchanges which determine the rato ot charge which will be. made between the various exchanges.

Figs; 6 and 7 show the meter control switches MS, and the distributing traine V1, as they are connected up tor exchanges UA, and UA2.

Fig. 8 shows, diaorammatically, the con- L! necting devices of a main exchange HA and a sub-exchange UA1.

A connection between the subscriber Tn, of the subeexchange Uli, and the subscriber Tn, ot the sub-exchange UAX will first be explained, both these subscribers being,` in the same trailic Zone.

When the subscriber Tm originates a call, the relay R, ot the presel-ector IVIV, opcrates in known manner and causes this preselector to set itselt on a free IIVlVl. l/Vhen this has been done, the following circuit is established: earth, battery, contact 11.1, windings I and II oi relay T1, wiper 2, contacts 3, 41,2, relay R2, earth. The relay T, in known manner stops the preselector, disconnects the calling); relay It, at the contacts and 6 and connects through the speaking' leads a, b at the contacts 7 and 8,1. At the second preselector ILVV the operated relay R, at contact 9,., closes the circuit oi the driving Ina-gnetl), and at contact 10,2 prepares the energizing circuit tor the test relay T2. The circuit of the driving magnet extends as tollows: earth, battery, cont cts 9,2, 11 mane net- D1, contacts 12,11, 13,2, earth. The tollowing circuit is established when the second preselector ILVV, finds a tree repeater' Ue and associated therewith a tree trunk line VL, leading to the main exchange HA: earth, battery, contact 10,2, wiw ,j and II of relay T2, Contact 14s wiper 15, contact 16, lead 17, Contact 18S, winding I ot relay Cl, contact 191, earth. The relays T2 and C, operate. The relay T, at contact'l 12a2 opens the circuit of the driving magnet 1) at contact 15,I2 short circuits its high resistance winding); I and switches through the testing and blocking lead from the first preselector 1.17117l to the repeater U@ and simultaneously disconnects the relay R, at contact 11,2. Furthermore at the contacts 2O and 21,2 the speaking leads are switched through to `the feeding bridge at the repeater Ue, which comprises the relays A, and B, whereupon both these relays operate.

At the repeater,'the relay C, closes its conlao * closes vthe contact ,5622 located in .parallel tact 22 and thus prepares a holding circuit over its Winding II. Furthermore at contact 2 8el theimpulsecontact 25al of relay A, conriecteltoA the lead 24 ofthe trunky line VLl. The operated relay A1 opens the contact 252 over Which are given the impulses for setting the `numerical -switches, at Vcontact 2621short circuits the relay VV2 While at the same time by opening contact 27.11 removing the short circuit from the Winding Il ot' relay'C1 and also opensthe impulse Contact 28a1 forthe magnet D2 of the auxiliary digit switch MSV yicrnong y,other circuit changes the relay Bl ,Opens its Contact 29.1.1, thereby removing .the -s liortcircuit,round the Winding I of relay V1. The latter operates, opens itscontact 19, 30 vand 33,., .and .closes vits contacts 31 and 32.2. llhe lclosure of .the contact 32.., causes the rotary magnet VD2 of ,the ,auxn

giliary .switch to ,be connected up zzearth, contactsQvl;S4V2,Wiper 35, Contact y861nagnet ,Damn battery, earth. The Wiper 35 moved lon tothe second contactl7 and thereby the following circuit is closed z, earth,

.contacts 3.2m '3.4m Wiper ,35, Contact .3.7, :lead .38, Windingofthe repeater', contact 4,0.,2.

leadetlfefthetrunk line .VLn Contacts-e202, 4 1.,'relay N2, Winding 2l, contact44-otthe -auxiliaryswitch MS2, Wiper A4,5, ,resistance 4 6', battery, earth. The relay Y. Operates, opens its .Contact 46m and .closes itscontacts 71m 148%: :49%: and ove' At Contact sur ythe rotary magnet Dams@ of y the auxiliary digit V.switch MS2 is connected to the Yimpulse .contact v5l ol .a relay A2, vwhileat the. contact 349m, thelirstlgroup selector ot' .the ,main rexchange is taken .into

fuse over. the `iiollowing circuit earth, .contact .49v2, relay C2, resistance 52, contact 5322, Vlead ,54, off-'normal contactk ofthe `first 4group selector I.GV Winding l `of vrelay .B2 .Winding I of relay (12, battery, earth. .The 4vrelays V C2 2) as .Well :as ,B2 and 03 Y(Fg- 3) werdt@- The .relay .C2

tk contact57c2 the 582.2 the relay yV3 is .maintained energized.

after' its original.l energizing circuit is. opened .atcont act 4202. The-holding circuitextends as ,tollowsz ,'earth, battery, resistance 46,

.Wiper 45, contact 44, Winding l offrelay V3, Ilead.6( normal Contact 6l, Wipe-r 6 2,.contact 5822, earth. At the lirst group selector' .LGWH the relay'Ca byclosin-g the contact l,6322 prepares aholding circuit, over bot-hits windi-n gs `I and .I I, which becomes operative as :soon `.as Vthe contact I5,51 1s opened Lat the `firststep of the group select-or. Therelay .B21- at. itscontacts .64.;andU-65b2 connects the relay A3 to theileadnnd.. conne'tsrthe Wind- A,ing Il ,oftrelay Bgrtogtliedeaph). llheiinl y pulses of the irst train transmitted by the earth, battery, resistance 7o, contact (4t2,

sumed that tor this connection lonlyasingle payment has to bemade,sincethensub-exchange DAX hes in the Sallie tralic zone asthe sub-exchange UAI. If for instance thelirst vtrain of impulses comprises three impulses, then all the three numerical .switches (LGWl, MS2, MS2) aremovedon three steps. The impulses are sentin lrnown niannerby interrupting the loop at thecalling subscribers station, so that therelaysA1 and B1 release et @eeh impulseend the relay A1 closes itsimpulse,contacts25al andQSw 'lhecircuits for operating the differentapparatus extend as follows 1- For the euXiliary digit .Switch .MSLD the sub-exchange: earth, contacts 32v2,'6 7f, 2821, 86, magnet D2, battery, earth.

2. For the impulse receiving relays A2 (Fie 9) and A3 (Fia 3.) ,in 'themin @X- change: earth, contacts-2521, 1) 2321, lead24, thence over re l ay A2,..contac t 5020., resistance (58,.batteiy, earth, andalso thence over contact 69m, lead 66, Contact 64m, relay AR bilttCl-ZY, L@arth- Y The relay A3 in known manner brings about the setting ojf LGrlV1 on the thirdgleyel. The relay A2 (Fig. 2) closesthexcircuit.for the driving magnet Dams?) as follow s,earth, contact 51,12, Windingsljlot relay Y2, contact 48V3, magnet D302@ battery, earth. Hence at thev end of the trainofiinpulses the Wipers 45 and `62 of the auxiliary switch MS2 stand o n the contacts 70. an d 71 respectively. l/Vhen the relay V3 has -released, it cannot be again energized during the further setting up of the connection. It should, howerer, here be notedthatas soon as th-erelay C2 is energized, the relay vU 2 is also energized as follows overits Windingl:

earth, contact 7222, Winding I vof relayv'U2,

contact 731,1., driving `magnet ID4 o t the counting switch yZS2, battery, earth. The magnet D,l is not energized yowingto gthe lhigh resistance oi? Winding l of relay U2. The `relay U2 has therefore opened its Contact 74u and thereby prevents the magnet .133(,2225

being connected up after relay V2 releases.

Vtacts 34,22 and 40,2 and closes the contact 742.

VBattery is thereby connected,overresistance 7 to the lead 4l ot' the trunk line Vlg-and .the relay B2 (Fig. 3) is thereby maintained energized over its winding as follows?- lead 41, contact 57,2, normal contact 76 and wiper 77 of the switch ZS2, junction point 78, contact 7 91 lead 59, contact 651,2, winding II of relay B2, earth. The relay B2 is also connected to the junction point 78 (Fig. 2). It is, however, of high resistance and is so much shunt-ed by the winding II of relay B3 (Fig. 3) that it cannot operate.

The first group selector LGVV, in known manner hunts for a free trunk line VL2 and the connection is completed by the positioning of the other numerical switches (e. g. the IIGIV, and LIV, shown in Fig. 3).

It is assumed that the final selector LV2 is provided with a side switch and that the impulse relays A, and Br are disconnected after the transmission of the trains of impulses for operating the driving magnets. It is also assumed that position 13 is the speaking position of the side switch, into which it goes after the wanted subscriber T12., has answered and in which position a feeding relay Y :tor the subscriber T115 is connected up. In position 13 of the side switch, battery is connected to the lead 82 over a resistance 80 and the side switch contact 81, so that the relay B2 in Fig. 2 is energized as follows: earth, battery, resistance 80, side switch contact 81 (position 13), lead 82, Contact 83 and wiper 84 of the second group selector II.G'W contact 8522, contact 86 and wiper 87 of the first group selector I.G\V contact 881,1, lead 59, contact 7913, junction point 78, relay B2, earth. The relay B2 operates and causes the switch ZS2 to move on to the next contact since the circuit for the driving magnet Dimm is closed as follows:-earth, interrupter 89, contact 901,2, off normal contact 91m,I of the switch Z811, magnet Dimm), battery earth. Hence the wiper 77 of ZS2 is moved to the contact 92. The magnet D4 cannot be again operated,

since the contact 9111,1I has now been opened. The relay B2 furthermore at its contact 931,2 connects earth to the relay A2. In addition the relay 13 is connected over contact 10412 to the lead 54. The relay S, operates, opens its contact 53S, and closes its contacts 99S1 and 1125,. At the contact 112s1 the relay U2 is maintained energized over its 'winding II.

To return now to the circuit changes, which take place in the calling sub-exchange UAI: it has already been described how the first train of impulses, which operated the first group selector I.GW also moved on the digit switch MS, for instance to the contact 94. At the end of this train of impulses, the relay U, is energized as follows: earth, contacts 32,21, 34,2, wiper 35, contact 91, relay U, contacts 1191 and 1202 battery, earth. The relay Il, connects itself in a holding circuit at its Contact 12111, g this circuit can, however, only be closed so long as local connecting devices LW1 accessible from the preselector ILVVV1 are free, since only in this case is the contact 1222 closed. The second train of impulses for setting the second group selector IIGVV1 causes the driving magnet B11121211 of the digit switch MS, to be operated in the same manner as did the first train of' impulses. Thereby the wiper reaches for instance the contact 118. After the release of relay V2 due to the prolonged short circuit of its winding I at contact 2611 the relay F is energized: earth, contacts 32,2, 34v2, wiper 35, contact 118, windings I and II of relay F, battery, earth. The relay F closes its contact 95 and thereby connects itself in a holding circuitdependent on the contact 96v1 of the slow releasing relay V1. Furthermore the relay F opens the contact 671, so that the rotary magnet D2 (m21) cannot be operated further by other trains of impulses.

It at the end of the conversation the wanted subscriber is the lirst to hang up, the side switch. ot the final selector LI,A reaches the position 14. The circuit for the relay B2 (Fig. 2) is however maintained, since in this position also the cont-acty 81 (Fig. 3) is closed. Then the calling subscriber T11, (Fig. 1) also hangs up his receiver, the rel( y A, is permanently de-energized, hence the contact 2611 remains open and the contact 27al remains closed. The winding II of relay C, is short circuited, and the relay C, therefore releases. Among other circuit changes, it opens its contacts and 231,., andcloses its contacts 97 and The circuit of winding I oi the slow acting relay V, is opened at contact 22,2. At contact 971 however the following circuit is closed: earth, battery, winding II of (l0 Jehu.

relay V1, contact 9711 lead 21, winding I oi relay A2, contact 931,2, earth, so that the relay V1 remains energized in this circuit. T he relay A2 also operates and gives a metering impulse to the meter impulse repeating relay ZR at the repeater Ue of the exchange UAI over the. following route: earth, battery, contacts 99s 10012, relay IIR, contact 571,2, lead 11, contacts 40v2, 981.11, relay ZR, contact 31,2, earth. The re lay ZR closes its contact 101,1 and thereby connects the low resistance 102 in parallel with the high resistance 102) to thelead 17 coming from the second preselector ILVVl. Thereby the current flowing over the meter Z at the first preselector IVV, is increased to such an extent that the meter can operate and the conversation can be metered. After the relay HR has been energized, the driving magnet Dimmu) of the switch Z511 is energized as follows: earth, contacts 51,2, 105111., `magnet 1),(2111 battery, earth. The relay HR at its contact 106111. short circuits the relay A2, hence it releases. The wiper 77 is moved on one step by the magnet D4 and reaches the Contact 107. The relay B2 is now short circuited because earth is con- 4neetedtoithejnnetiompoint-78 over the .con- ...tact .5822, wiperffthe contacts '71 and 1.107 'the-wiper7f7. {Therelay BTreleasesand .opens thel contact-S93 and 104. .The-openz'irigfoi contact 1,1(),4b2iinterrupts Ythe holding circuitover the yrelay-s 2,52 and C3, and thefirstgroup Vselector' -JLGW1 .-as well ,asthe 'succeeding vswitches-are lreleased in known mannen lVhen the `contact 9.3132 is opened, the relay V1 at the repeater Uc'is-deenergized -fand relea ses.

T *he digit switches MS, and MS2 fas well ias-,the vcmlnting switch ZS2 are released .in the i. following 2 man-ner z cAfter the release of relay V1 t-herelays V2 fandS are .energized inthe following fronte: .feartln contact 33.2, winding `Il of lr-e lay";V2, .off normal fr contact 107 kms, of the digit switch MSI, windingIIfoi-relay S, battery, earth. Both the Arelays `Sfand V2 operate :and closelheir contacts 108.2and ,1109s. rllhereloy 4:the following circuit is closed for the lrotary. magnet 113mm): earth, contactsillOm v 1095, 108,2, 67f, 2821, 86,'magrieti-D2, batter-y,earth. The ma-gnet`D2 op- .erates,fmoves ongthedigit switch and at its contact 1111.12 short circuits :the relay V2. vThe relay V2-releases `and opens its contact 5108, whereby the magnet D2 releases .and lopens athe contact .111. The relay V2 now -again operates and again closes e the contact 08.2. Thiseycle .isrepeated until the auX- .i-liarydigit switchireaches its normal posi- `lion, wherein .the'of normal contact 107mm -fis` opened. After the release of the rotary magnetD2 it is impossible for the relay V 2 .-to again energize.

'Bhe r1.'elayU2 in Fig. 2 was, as .already mentioned, maintained energized during Vconversation over-a Contact 1120i relay'S1 and-its winding Il. vSince the relay S1 was .desenergi-zed after the :release of relay B2, -thefrelay U2 isalso deeenergizedand closes .the iollowing circuit for the magnet Daman: earth,'battery, magnet', D3, contact `46.3, oli' normal contact 113,.,52 o1 the digit switch "MS2, contact 7.4.12, winding II oi' reflay IIR, earth. The magnet D2 .operates andcloses the Afollowing circuit: earth, battery, winding II of relay U2, contact 11423, .winding III of rela-yHRearth. The relay U2 at contact `7422 opens the circuit of the y-inagnet Dm whereupon the magnet releases andfopens the circuit'ofthe relay U2. This .cycle is repeated until the vdigit .switch reaches its normal position, in which the ycontact 113121,52 is opened.

IThe switch ZS2 is moved into its normal position at the Vsame time as the digit v switcl-i MS2, ,since the circuit of .driving fmagnet D ,Qzsm is closed as follows: earth, "battery, lmagnet D2, off normal contact 115mm, nor-- mal .contact 1161.221, contact 11722, winding .Il yof relay .'Hr, .earth. The .mag-net .D2 ,also closes a .contact.1.1.8.1.1r .inthe circuit @of wind.-

1205 lat the .last mentioned first numerical iclosesfthe'contact r 174.12, Irelay HR, winding II, earth.

ing ,II .of .relay `U2,-so that .the .movingnn of the. .switc-h.-ZS2 ,is dependent only on V.the operation s of Athe `magnet D4 .and .the .relay U2. .The drivingcircuit forthe magnet D4 is yiinal-ly :opened when the yswitch .ZS2 .rea-ches'its normal position since ,the contact Hence the first` group -selector .is .set on `the .eighth Lle.vel,in which Vit takes into 'use .a nfree` trunk Vline V145. The continuation 'of thei'trunlrline *VL5 is .indicated by VL, in

.Atthepoint (20o, .20.1, 202) where .these two .lines.-meet, ;a trunk line VL, .is

connected coming from the bank contactsfof those first numerical switches 1 (LGW2) that `:are accessibletosubscribers of the mainexchange. :Between lthecontacts 203, `204 and .switch V1.(J`rVV2and the meeting points 200, 201 .and 202 are located .the meter operating devices that `are:` only operated for calls originated bythemainexchange subscribers. NThese meteroperating devices 1,(MS3, ZSl/ .fZS2r) are therefore not employed .for the ibefore and vprevents the .rotary magnet D,2

:bei-ng operated .by further .trains iof mpulses.

The wiper 4510i the digitswitch yMS2 .is .likewise set on Vto the veighth contact, which .in fFig. 2 is designated by 121. The winding H1 of :relay HB fisshort'circ-uited for -the duration .of the impulse train yby the contact 4722. The .relay :HR is, however, ener- -gized upon 'the release of the relay V2: earth, battery, resistance 46', wiper 45,-.con- .tact .121, 'relay.HR, winding 51H, earth. The vrelay SHR-operates and by opening the contact .7 '31 interrupts .the circuit overfthe winding I of -relay U2. The relay U2 releases and 7422, whereby the following :circuit'is closed for kthe magnet D2: earth, fbattery, `magnet D2, contacts `46%, ,113kms2, The magnet Dm by closingits contact 1114,13, energizes l the rela-y lU2 vover its winding II in series with ithe .winding .III of relay HR.

The relay 'U2 .opera-tes Vand opens the Vcon- 1 'tact 74..,2, vwhereby :the circuit for the mag- :net D2 is opened, so that it de-.energizes and opens thecontact 114.13. Thereupon the relay .releases and closes contact 74.12. This cvn'le is repeated until the wiper 45 reaches f the contact 122. This contact cannot be reached by the first train of impulses transmitted by the calling subscriber which will never exceed ten. As soon as the wiper 45 reaches the contact 122, the following circuit is established: earth, battery, resistance 46, wiper 45, Contact 122, winding I of relay V3, lead 60, contact 123, wiper 62, contact 5862, earth. The relay V3 operates, opens the circuit for the automatic rotation of the digit switch MS2 by opening the contact 46,3, and at contact 48v3 connects the rotary magnet D3 to the impulse contact 51,2. The digit switch MS2 has now been brought into a position in which it can be operated by the second train of impulses. The transmission of the second train of i1npulses causes the relay A2 to be operated in the manner already described and the relay at its contact 51a2 sets the rotary magnet D3 in operation: The circuit of the rotary magnet D3 contains the winding II of relay V3, so that this relay remains energized for the duration of the train of impulses. The energization of the relay V3 after the switch 45 has been set on the contact 122 also causes the relay HR to release, thus preventing the rotary magnet D4 of the switch ZS2 being operated by the relay A2.

Let `it be assumed that the second train of impulses comprises only a single impulse and hence the wiper 62 of the digit switch MS2 has been set on the contact 124, over which is connected up thereafter wiper 125 of the zone switch ZSl.

After the connection has been set up and the wanted subscriber has answered in the manner'already described, the relay B2 is energized and causes the switch ZS2 to take one step as before; hence the wiper 77 of ZS2 stands on contact 92. Furthermore the contacts 126 and 127 are closed in this position of ZSZ. The relay S1 has been again operated over the contact 1041,2 in the manner already described and has connected up the relay U2 over its winding II so that the contact 1282 is opened and the contact 129,12 is closed.

The meter operating device has a time switch associated with it, which is moved on by the magnet D5 at fixed intervals of time. After the contact 129112 has been closed, the time switch is moved out of its normal position since the magnet D5 is energized as follows: earth, interrupter 130, contacts 1311) 126m, normal contact 132m, contact 129m, rotary magnet Dze), battery, earth. At the first step of the time switch ZE the contact 132ze is opened and the contact 133,., is closed.

It is assumed in the present example that 2the time switch has 36 contact positions and is moved on by a time contact 134,11., which is closed every 5 seconds; it may for instance be operated by an electric clock. Hence one rotation of the time switch corresponds to a duration of 3 minutes, which has been assumed to be a unit of time for the calls. The contact 134 is closed shortly before the time switch has completed a rotation. Thereby the corresponding subscribers are given a buzzer tone, from which the recognize that a 3 minute period will e completed in a few seconds and that further charge will be made if the conversation is continued. The circuit for repeating the signal, which is closed upon the closure of the contact, extends as follows: earth, secondary winding of the induction coil 135, contact 136,3, wiper 137, contact 134m Winding II of relay B2, winding II of relay A2, earth. The buzzer tone is repeated from the windings II of the relays A2 and B2 to the windings I of these relays and can therefore be heard by the subscribers. When the time switch upon its rotation reaches the last contact (the 36th) the driving magnet D6 of the zone switch ZS1 is energized as follows: earth, 135, contact 136,3, wiper 137, contact 138,2, magnet Demi), battery, earth. The zone switch ZS1 is moved on one step. The circuit changes just described are repeated at each rotation of the time switch ZE.

The zone switch ZSl, which is controlled by the time switch ZE, has its contacts connected with the contacts of the counting switch ZS2. The wiper 125 of ZS1 is connected up for calls to the second traffic zone. The normal contact 139 is connected with the fourth contact 140 of the switch ZS2. Since this switch is set on the rst contact 92 as already mentioned, it has to take three steps before the wiper 77 reaches the contact 140. Hence for connections inthe traffic zone II, three metering impulses have to be transmitted for each conversation unit..

When the zone switch ZS1L has been advanced one step at the end of the first unit of time, the wiper 125 stands on the contact 141 which is connected with the seventh contact 1.42 of ZS2.

For calls to the traffic zone III the wiper 143 is connected up, as has been assumed in Fig. 2. The normal contact 144 upon which this wiper is standing, is connected to the sixth contact 145 of ZS2. Hence for calls to the third traflic zone five impulses are transmitted for each time unit.

For calls to the fourth tralic zone, for which the wiper 146 of ZS1 is connected up, seven metering impulses have to be transmited for each time unit, and for calls to the fifth traflic zone nine metering impulses have to be transmitted.

In the present system, devices are also provided for limiting the duration of the different calls according to their value. This is achieved by means of the switch ZS2. In the present example this switch has 32 positions. The last five contacts 147 to 148 are inultipled together andare connected with a relay TR. Since the zone switch ZS1 is always moved on one step at the end of a three minute period, the wiper 125 of the zone switch ZSl reaches the vninth contact 149' at the expiration ot E3 time units in the case ot callsto the tratiic zone 1I: the. conta'ct1l9 is connected to the contact 147 of the switch ZS2. When the call has lasted'so long, i. e. 24jminutes, the relay T2 is energized in thelt'ollowing circuit: earth', con tact 5822, wiper 62, contact'121l, wiper 125, contact'19, lead 150, contact V14:7, relay T3, battery, earth. The relay T2 operates, opens its contact136v and connects the buzzer tone at its contact 151 to the windings'II of the relays A2 and B2. The calling subscriber therefore immediately receives the buzzer tone. ln addition, however, the contacts G9 and 7923 are also opened andthe contactv 152,2 Ais closed, hence the speaking connecticn is interrupted. However, the relay B2 is maintained energized over the contactv 152,3 andthe resistance G8.

Ita connection has been setup to the trattic zone V, then the wiper 62 of the digit switch MS2 stands on the contact-s 153, so that the wiper 154 is connected up. Thenormal contact 155 of this switcn is connected with the tenth contact 156 otthe switch ZS2. Itris assumed that for a connection of such high' value the ma Vzimum duration of a conversation is two units of time. 'the wiper 154 of the switch ZS, is at the end of the iirst time unit moved on to the contact 157,which is connected with the contact 158 of ZS2. At the end `ot'the second time unit the driving magnet D6 oic ZS1 again receives'an impulsey and the wiper 154'reaches the contact 159, which is connected with the contact 150 of ZS2'. The relay T2 is then at once energizedv and brings aboutv the circuit changes already described.

Vhen the calling subscriber hangs'uphis bythe relay HR" is again energized and by closing the contact 105 connects the driving magnet D.,L of ZS2 to the impulse contact 5122.. The relay HR at its Contact 1061lr short circuits the relay A2, so that the relay A2 slowly releases and opens the contact 5122 in the circuitiot the magnet and also the contact 10022 in the circuit et relays HR and ZR.

The magnetD4 releases and `after a little while the slowacting relay HR also releases. Thereupon the relay A2 again operates and causes theY transmission ot a second meteringimpulse and the moving env of the switch ZS2'. VZjreachesv a-contact, over which the relay B2 is short circuited. It the zone switch ZS,

This cycle is repeated until the wiper;

was moved on three times-during a conversa'- tion in the second trafficV zone, thefwiperx125`" i stands on thecontact-161, which is connect'- ed with the contact 162 of the' switch* ZS2. When the wiper 77 reaches thisA contact, thel relay B2 is shorty circuited, since earth is connected to the wiper 77 over the contact 5822, wiper 62, contact'124t, wiper 125, con-v tacts 161 and 1621. Therelay B2 releases, opens contacts 93 'and y104522, whereby the re lays C2 and Sl are permanentlyr de-energized As soon as the` transmission of metering impulses commenced'the c0ntact127222 wasz opened, this contact being ,closed only in the first position ofthef'switch ZS2, that is when the wiper Wstands on the contact 92. Thus the operation ofthe timeswitch ZE is prevented during meter `impulse transmission.4

The switches MS2, ZS-1 and ZE are movedy on into their normal position when the'relay- C2 is de-energized after the release-ot relays B2 and S1. The moving on of the time' switch ZE is effected by the alternate operation ofthe driving magnet D5 andthe relay/f U2. The circuit of 'the driving magnety D5 ofthe time switch ZEl is closed over: earth, battery, magnet D2, contact-12822, oil1 normal Contact 1701222, relay HR winding II, earth. The magnet D5 closes its contact 171g,5 andV thereby energizes'th'e yrelay U2, which-opens the contact12822, so that'Dv is de-energized. rlhe relay U2 is nowv de-energized and yagain closes its contact 128,12, so that the magnet D5 receives another-impulse. The contactv 170kze is opened when the time switchy 2191001"` magnets D3 and-D2, which move the'di'git11lf0 switch MS2 and the zone switch ZS2 respec` tively'` intothe normal' position, havef al-t ready been previously described. i

The trunk line VLl` cannot be taken `into nseso .long as any ot the switches MS2, ZS1 115? or ZS2 remain in the :operatedf condition.A This is due to the relay HR which at Yits con# tact 146 closes a circuit'for therelaySat'the repeater Ue (Fig. 1). As already men'- fr tioned, the relay Sis energizedover the oft? if The magnet D,l energizes therelayi 1051:

18s open, so that it is impossible for the trunk line VL, to be taken into use by a testing second preselector ILVWl.

It a call is set up between the subscriber Tn3 of the main exchange HA, (Fig. 4) and a subscriber of an exchange accessible over the trunk line VIM, the relays GG, A, and B6, are energized after the preselecting devices IVW2 (Fig. 4) and IIVW, have been positioned. Thereafter in lnown manner the first numerical switch LGW, is set on a level to which the trunk line VL8 is connected. When such a free trunk line has been found, the following circuit is established: earth, windings I and II of relay P3, contact 206m, wiper 207, contacts 205 and 208,8, relay C7, lead 209 of the trunk line VL9, junction point 202, lead 210 of the trunk line VL6 to battery over switching devices of the selectors in the distant exchange. The relay C7 closes the Contact 211C7 located in parallel with the contact 208v8 and energizes the relay V8 over the cont ct 2120 the contact 213 of the digit switch MS3 and the wiper 214, Relay VS opens the contact 208V8 and at contact 215V, connects the relay A, to battery over the resistance 216. Between the trunk lines VLS and VL, lie the switching members of the meter operating devices, comprising the switching devices MSg, ZSl and ZSZ. The method of operating these meter operating devices corresponds to that shown in Fig. 2, so that it is unnecessary to describe the circuit changes. The relay B, corresponds to the relay B3 and the relay 'Il1 corresponds to the relay T3.

That I claim is z* i. In a telephone system, calling and called lines, numerical automatic switches for establishing connections between said lines, other switches, means for transmitting impulses to said switches to cause them to perform switching operations during the process of setting up aconnection, and means tor then causing said other switches to automatically move into a definite position from which they are again moved a dist-ance dependent on the number of impulses in the subsequent train ot impulses of the called number.

2. In an automatic telephone system, means including a plurality of automatic switches for bringing about the establishment oli connections between calling and called lines, auxiliary switches associated with said automatic switches, said automatic switches and said auxiliary switches responsive to each impulse ot a plurality of trains of impulses, and means for causing said auxiliary switches to automatically move a detinite distance between a plurality of impulse series.

3. In a telephone system, an automatic switch, another switch, means for transmitting impulses to said switches in accordance with a digit of a called number, means for then causing said other switch to automatically advance to a deiinite position, the first means being then eiective to again move said switches in accordance with a second digit oft a called number.

4. In telephone system, a train of automatic switches responsive to series of impulses to establish talking connections between calling and called lines, another automatic switch responsive to the impulses of one series and non-responsive or responsive to the impulses of a succeeding series dependent on the number of impulses in the first series.

5. In a telephone system, an automatic switch, an auxiliary switch associated therewith means for transmitting impulses to said switches to cause the same to move a corresponding number ot steps, means for then causing said auxiliary switch to automatically move to a deiinite position beyond any position attainable by a single impulse series, and means responsive to the delinite positioning oi' said automatic switch to again render said auxiliary switch operative responsive to a subsequent train of impulses.

6. In a telephone system, a calling line` automatic switches, an impulsing relay, means at the calling line for transmitting impulses to cause said relay to repeat impulses to operate one ot said automatic switches to establish a connection and means for thereafter causing said impulsing relay to automatically transmit impulses to move another of said automatic switches a distance dependent on the time lapse ot the connection.

7. In a telephone system, automatic switches, means including an impulse repeating relay tor transmitting a series ot impulses to position said switches, one ot said switches being positioned to extend a calling line towards a desired called line, another of said switches being positioned to determine the `routing ot' the call, a third one of said switches being positioned to determine the value of the connection in case a particular route is taken, a fourth automatic switch, and means automatically controlled by said impulse repeating relay, subsequent to the positioning of said other switches, for causing the same to automatically operate said fourth switch a distance dependent on the position ot one ot' said lirst switches.

8. In an automatic telephone system, a calling and called line, means including automatic switches for establishing a connection between said lines, auxiliary switches associated with said automatic switches, means controlled over said calling line for positioning said switches, and means dependent upon and subsequent to the operation of said first means for causing said auxiliary switches to automatically move a detinite distance.

9. In a telephone system, a calling' line,

automatic switches', animpulsing relay, auxmove; said auxilaryrswiltchesi a distance deillary.swltchesyimeans at the eallmg Ime pendentzuponthe txlmel lapse of tlaeg-eonnecfor transmlttmgzflmpulses :to cause salclvrelay tlon.

10 to repeat mpulsesto-operate said automatic Signedby lnemtf-Bezlv'lnf Germany 'this l switches and said auxiliary switches, and 175th clay Of'-August,r 1923.

means for thereafter causing said impulsng relay io` automatically transmit impulses to AERNST HGB-N. 

